Soldier of Fortune II: Double Helix is a video game created by Raven Software, a sequel to first game Soldier of Fortune. It was developed using the Quake III: Team Arena engine. Once again, Raven hired John F. Mullins to act as a consultant on the game. Based on comments and criticisms of the original game, Raven Software developed Soldier of Fortune II to be a more "realistic" game, with tactical shooters like Operation Flashpoint and Tom Clancy's Rainbow Six as inspirations rather than Quake. A sequel titled Soldier of Fortune: Payback, made by Cauldron HQ was released for Microsoft Windows, Playstation 3 and Xbox 360 in 2007.